Digital Commons Network^™

Spatial Conservation Planning In The Southeastern United States: Alignments And Opportunities, Bradly Stewart Thornton

Theses and Dissertations

Conservation managers and planners need the ‘best available science’ to support robust and defensible decisions, ensuring that public resources are appropriately allocated. Spatial planning products and decision-support tools developed for this purpose should enable partner organizations to achieve focus, coordination, and increased effectiveness in their investments and actions. Whereas conservation partnerships have historically created distinct planning tools, there is increasing interest for improved coordination, communication, and unifying biological datasets to improve the cohesiveness of regional management activities. We sought to inform spatial conservation planning efforts in the southeastern United States through the development of species distribution models for focal avian …

Advancements In Geospatial Monitoring Of Structures, Jordan Keith Baldwin

Theses and Dissertations

The need for advancements in geospatial monitoring of structures has evolved naturally as structures have become larger, more complex, and technology has continued to rapidly develop. Greater building heights generally lead to greater challenges for surveyors, limiting the practical use of traditional measurement methods. For this reason, a new complimentary method was developed and implemented to support elevation monitoring activities during construction of the Salesforce Tower in San Francisco, California. While some studies have explored the use of strain gauges to monitor strain development within individual members, the primary contribution of this work is that it presents a practical and …

An Analysis Of Text-Based Machine Learning Models For Vulnerability Detection, Kollin Ryne Napier

Theses and Dissertations

With an increase in complexity of software, developers rely more on reuse and dependencies in their source code via code snippets. As a result, it is becoming harder to identify and mitigate vulnerabilities. Although traditional analysis tools are still utilized, machine learning models are being adopted to expand efforts and combat such threats. Given the possibilities towards usage of such models, research in this area has introduced various approaches which vary in usability and prediction. In generalizing models to a more natural language approach, researchers have opted to train models on source code to identify existing and potential vulnerabilities. Exploratory …

Predicting How Science Self-Efficacy And Identity Contributes To Postsecondary Stem Degree Selection, Bo Jason Hayes

Theses and Dissertations

One of the earliest indications that a student may be interested in STEM paths is the students’ own self-efficacy for science as well as how they may see themselves in a STEM career as part of their science self-identity (Schlegel et al., 2019). Currently, there is a need to contribute to research that can assist agencies such as the National Science Foundation (NSF), Department of Education and the National Academy of Sciences in advising the nation, including high schools and postsecondary institutions on ways to increase the enrollment of students in STEM-related careers. This study examined the extent to which …

Physics-Based Modeling Of Post-Wildfire Landslides In Unsaturated Hillslopes, Masood Abdollahi

Theses and Dissertations

Changes in climatic regimes and land use have led to increases in wildfire activities around the world. Wildfires are now happening more frequently, at higher altitudes, and higher severities. Adverse impacts of wildfires can last years after the fire has been contained through post-fire geohazards, such as shallow landslides. Post-wildfire shallow landslides are often mobilized by rainfall and due to fire-induced changes in soil and land cover properties and near-surface processes. This study aims to develop a physics-based framework to evaluate the stability of burned hillslopes against rainfall-triggered shallow landslides. A coupled hydromechanical infiltration model is developed by employing a …

Host-Acquired Virus Genes Support An Ancient Antiviral Role Of The Pirna Pathway In Dipterans, Rebecca Christian

Theses and Dissertations

Endogenous viral elements (EVEs) have been recently investigated as a source of transgenerational immune memory. These “viral fossils” are abundant in Aedes mosquitoes and partner with the host’s primary antiviral defense system, the RNA interference (RNAi) pathways. This partnership appears unique to mosquitoes, which encode an expansion of the Piwi endoribonucleases. To interrogate EVE-Piwi partnerships and their role in antiviral defense, I performed a comparative small RNA analysis of two naturally occurring EVE-virus pairs – one in the mosquito Aedes albopictus, and one in the midge Chaoborus americanus. Both express an EVE related to the nucleoprotein of their …

Developing Systems Engineering And Machine Learning Frameworks For The Improvement Of Aviation Maintenance, Fatine Elakramine

Theses and Dissertations

This dissertation develops systems engineering and machine learning models for aviation maintenance support. With the constant increase in demand for air travel, aviation organizations compete to maintain airworthy aircraft to ensure the safety of passengers. Given the importance of aircraft safety, the aviation sector constantly needs technologies to enhance the maintenance experience, ensure system safety, and limit aircraft downtime. Based on the current literature, the aviation maintenance sector still relies on outdated technologies to maintain aircraft maintenance documentation, including paper-based technical orders. Aviation maintenance documentation contains a mixture of structured and unstructured technical text, mainly inputted by operators, making them …

Relaxing Dc Capacitor Voltage Of Power Electronic Converters To Enhance Their Stability Margins, Ali Zakerian

Theses and Dissertations

Recently, due to the increasing adoption of distributed energy resource (DER) technologies including battery energy storage (BES) and electric vehicle (EV) systems, bidirectional power converters are becoming more popular. These converters are broadly utilized as interface devices and provide a bidirectional power flow in applications where the primary power supply can both supply and receive energy. A dc capacitor, called the dc-link, is an important component of such bidirectional converters. For a wide range of applications, the converter is required to control the dc-link voltage. Commonly, a proportional-integrating (PI) controller is used by the dc capacitor voltage controller to generate …

Examining Food Insecurity Among Mississippi Community College Students, Laura Jean Kerr

Theses and Dissertations

Food insecurity among postsecondary students and especially community colleges is a persistent social problem, but the prevalence continues despite much research. Postsecondary students experience food insecurity slightly differently from the general population and they are held to different rules to qualify for food support such as the supplemental nutrition assistance program (SNAP). In this research I examine the prevalence, frequency, and duration of food insecurity experiences among Mississippi community college students. I begin with a discussion of the literature of food insecurity and policy used to address food insecurity. I draw upon Bourdieu’s theory of social fields, capital, and habitus …

Halide Substitution Of Ternary Bismuth Chalcogenides For Photovoltaic Applications, Thomas Boggess

Theses and Dissertations

Semiconductors play an integral part in modern society. From computing to LEDs their use is ubiquitous, and no field is more reliant on them than that of power generation. Current political movements have seen a push to decrease reliance on traditional forms of power generation, which relies on fossil fuels, to renewable sources such as solar power. However, current commercial solar panels, based on silicon, are lacking in efficiency, only reaching between 18% and 22% efficiency.¹ In recent years, materials called perovskites have been garnering significant attention as possible replacements for silicon cells due to their favorable optoelectronic properties. …

Role Of Fungal Arv-1 Protein In Sterol Metabolism And Pathogenicity Of The Chestnut Blight Fungus Cryphonectria Parasitica, Soumyadip Kundu

Theses and Dissertations

Intracellular sterol redistribution is an important step in the lipid homeostasis of organisms, a process directly linked to the organizational arrangement in the plasma membrane (PM) of cells. Previous studies in the budding yeast Saccharomyces cerevisiae have demonstrated that the ARV1 (ACAT-related enzyme-2 required for viability 1) protein is a major regulator of sterol transport from the endoplasmic reticulum to the plasma membrane, contributing to the structural organization of the PM, rendering it resistant to anti-fungal compounds as well as maintaining ER integrity. This study assessed the significance of ARV1 in the plant pathogenic fungus Cryphonectria parasitica (Cparv1) …

An Investigation Into Perceptions, Expectations, And Development Of Professional Skills In Engineering Students, Morgan Kathryn Green

Theses and Dissertations

Upon graduation from an undergraduate institution, engineering graduates are expected to have a baselevel skill in technical skills related to their discipline. Teaching technical skills comes naturally to engineering programs as the conceptual understanding of the material form the foundation of engineering ability. However, engineering graduates also are expected to have a baselevel of professional skills, which are more subjective in nature and do not have a standardized approach for teaching or assessing them at the undergraduate level. An investigation into current perceptions of professional skills by relevant parties is an initial step in providing more structure to professional skills …

Comet Nuclei Activity Simulation Using Percolation Theory On Comet 67p/Churyumov– Gerasimenko, Ahmad Sohani

Theses and Dissertations

Comets, remnants of the solar system's formation, exhibits partially unexplained outbursts that are closely tied to the physical structure of the nucleus. To investigate outbursts, we employed pore network modeling techniques, such as the Bower-Watson algorithm and Voronoi diagrams, to better represent the nucleus' complex porous structure and simulate gas transfer processes. We examined heat diffusion in the comet's subsurface and its influence on crystallization. The extra heat generated by crystallization can shift the crystalline front deeper into the nucleus, accelerating subsurface evaporation rates. This process results in the formation of a thicker ice mantle with reduced porosity on the …

Development And Evaluation Of An Automated Tactical Tillage Tool To Control Weeds In Row-Crop Production Systems, Grace Mccormick Friday

Theses and Dissertations

Weed control is an integral part of a successful overall production strategy in row- cropping systems and has the potential to reduce or eliminate yield losses that negatively affect profitability. Timely and correctly selected herbicide applications are the major keys for effective weed control in a majority of instances. However, there are negative factors that contribute to ineffectiveness and weed escape issues that currently lack viable options for management. Sparsely populated late-season weeds that emerge after lay-by herbicide applications and weeds that have become tolerant and resistant to traditional herbicide chemistries are of greatest concern. Historically, these weeds would have …

Interactive Effects Of Bark Beetles, Ophiostomatoid Fungi, And Subterranean Termites On Wood Decomposition And The Biogeochemical Cycling Of Pine Forests, Kimberlyn Pace

Theses and Dissertations

A frequent source of pine tree mortality in recent years can be attributed to pine bark beetles and their vectored Ophiostomatoid fungi, an organism that has been observed to attract subterranean termites that preferentially recruit to this downed woody debris. This interaction may significantly modify biogeochemical fluxes in bark beetle mass mortality events, but studies are often limited to singular regions or single pine-dominated ecosystems. Two studies were designed to test the interactive effects of these associations on terrestrial biogeochemical cycles and decomposition processes, the first using replicated field trials in Mississippi, Arizona, and Honduras across two years and the …

Robotic Cotton Harvesting With A Multi-Finger End-Effector: Research, Design, Development, Testing, And Evaluation, Hussein Gharakhani

Theses and Dissertations

Cotton is harvested with large and heavy machines that are very efficient but have some disadvantages. They can harvest the crop only once at the end of the growing season. Since cotton bolls do not mature uniformly, the early opened bolls expose their fiber to weather for extended periods, reducing lint quality. In addition, the machines can also compact the soil, reducing water and fertilizer usage efficiencies and crop yields in the following years. Robotic cotton harvesting offers a promising solution to these issues. Smaller robotic harvesters could go to the field multiple times during the season to pick cotton …

Exact Solutions For Schrodinger And Gross-Pitaevskii Equations And Their Experimental Applications., Bhavika Bhalgamiya

Theses and Dissertations

A prescription is given to obtain some exact results for certain external potentials �� (r) of the time-independent Gross-Pitaevskii and Schrodinger equations. The study motivation is the ability to program �� (r) experimentally in cold atom Bose-Einstein condensates. Rather than derive wavefunctions that are solutions for a given �� (r), we ask which �� (r) will have a given pdf (probability density function) �� (r). Several examples in 1 dimension (1D), 2 dimensions (2D), and 3 dimensions (3D) are presented for well-known pdfs in the position space. Exact potentials with …

Navigating The Road To Distributional Social Equity Using Smart Cities Technologies, Annus Azhar

Theses and Dissertations

This dissertation aims to understand the mechanisms behind the adoption of smart cities technologies (SCT) and how they can promote social equity in local communities in the United States. There is a distinct lack of empirical research addressing the methods designed for the promotion of social equity despite their numerous benefits. The present study will address this omission in the scholarship by providing evidence-based insights on how public administrators can leverage SCT to promote distributional social equity through the Digital Era Governance (DEG) and Adoption Theory frameworks. This study also demonstrates the efficacy of applying the Technology Acceptance Model (TAM) …

Mitigating Adverse Impacts Of Increased Electric Vehicle Charging On Distribution Transformers, Akansha Jain

Theses and Dissertations

There is a growing interest in electric transportation, and the number of electric vehicles (EVs) is increasing. The resulting increase in EV charging power demand has an adverse impact on the existing power grids, especially the distribution transformers. The repeated and continued overloading caused by EV charging can significantly reduce their operational life. This dissertation aims to comprehensively study the adverse impacts of EV charging on distribution transformers and provide robust and practical solutions to mitigate it. A typical North American secondary distribution system with different EV penetration levels and four realistic residential EV charging scenarios are used for the …

Quantifying Seasonal And Annual Precipitation Variability On San Salvador Island, Bahamas Using Surface Observations And Satellite Estimates., John Bryson Wells

Theses and Dissertations

San Salvador Island is a small Bahamian island located in the subtropics just north of the Tropic of Cancer. Due to its subtropical location, the island is influenced by both mid-latitude and tropical weather patterns. These weather patterns vary in scale from localized convective uplift to synoptic-scale systems. This study compares satellite-derived estimates of precipitation and rain gauge observations from June 2019 through September 2021 to evaluate the relationship between the two datasets. This study then uses the satellite-derived estimates of precipitation over a 20-year period to quantify annual and seasonal variability in precipitation on San Salvador. Corroborating past research, …

Physiological And Proteomic Analysis Of Soybean In Response To Drought And Heat Stress, Amandeep Kaur

Theses and Dissertations

Drought and temperature stress are the two most important factors limiting crop productivity. A physiological and proteomic analysis of soybean was performed to investigate the negative impact of these variables. The previous studies reported the beneficial effect of silicon under stress conditions. Silicon supplementation may promote plant growth under drought stress, although the mechanism to alleviate drought stress is uncertain. The proteomic analysis of chloroplast proteins was carried out to study the response of silicon supplementation under drought stress.

Similarly, temperature stress, mainly heat stress, has an adverse effect on soybean plants. The comparative analysis of two soybean cultivars, DS25-1 …

The Consequences Of Low Energy Availability Related To Relative Energy Deficiency In Male Athletes: A Systematic Review, Lauryn Bailey

Theses and Dissertations

RED-S is a syndrome that stems from low energy availability (LEA) in athletes. It can impact numerous physiological and psychological functions, as well as negatively affect performance. Because RED-S is a relatively new syndrome, there are few studies showing the impact of RED-S on performance and physiological factors. The aim of this systematic review was to examine the consequences of induced LEA in relation to RED-S in male athletes. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, Five studies were deemed eligible based on inclusion and exclusion criteria. Studies measured risk of RED-S through body composition, bone …

Race, Gender, And Inheritance: The Experience Of Black Farmers In Mississippi, Gbenga Idowu Elufisan

Theses and Dissertations

The population of Black farmers in the U.S. has declined to 2% of farmers in the U.S. because of institutional racism, land dispossession, heir’s property, and youth’s disinterest in farming. Most works on Black farmers have focused on racism, and heirs’ property, but little is known about the influence of race, gender, and inheritance on Black farmers’ experience. To understand this, I asked: what are the contemporary challenges associated with farming among Black farmers in Mississippi? How do race, gender, and inheritance influence the experiences of Black farmers? And how do Black farmers cope with their farming challenges? Twenty farmers …

Design Of High-Power Ultra-High-Speed Permanent Magnet Machine, Md Khurshedul Islam

Theses and Dissertations

The demand for ultra-high-speed machines (UHSM) is rapidly growing in high-tech industries due to their attractive features. A-mechanically-based-antenna (AMEBA) system is another emerging application of UHSM. It enables portable wireless communication in the radio frequency (RF)-denied environment, which was not possible until recently. The AMEBA system requires a high-power (HP) UHSM for its effective communication performance. However, at the expected rotational speed range of 0.5 to 1 million rpm, the power level of UHSM is limited, and no research effort has succeeded to improve the power level of UHSM.

The design of HP-UHSM is highly iterative, and …

Secure And Efficient Federated Learning, Xingyu Li

Theses and Dissertations

In the past 10 years, the growth of machine learning technology has been significant, largely due to the availability of large datasets for training. However, gathering a sufficient amount of data on a central server can be challenging. Additionally, with the rise of mobile networking and the large amounts of data generated by IoT devices, privacy and security issues have become a concern, resulting in government regulations such as GDPR, HIPAA, CCPA, and ADPPA. Under these circumstances, traditional centralized machine learning methods face a problem in that sensitive data must be kept locally for privacy reasons, making it difficult to …

Eating German, The American Way: German And American Cooking Traditions, Potato Salad, And The Culinary Assimilation Of German Immigrants, 1820-1920., Scott Wooley

Theses and Dissertations

“Eating German, the American Way” explores how and why the mayonnaise-based potato salad came to be a staple of American culinary tradition. It examines how native-born Americans and German immigrants in the nineteenth century identified themselves based on their culinary traditions and what they ate and how the interactions between, and accessibility of, those traditions created a new identity based on the sharing of recipes as the two groups mingled and assimilated to each other. It uses food as a way to understand the processes of assimilation by defining the distinctions between the two groups based on their separate repertoire …

Protecting The Vulnerable: Tornado Sheltering And Communication Of Public Shelters With A Case Study From The Covid-19 Pandemic, Craig Douglas Croskery

Theses and Dissertations

One of the greatest natural hazards that is faced with in much of the United States are tornadoes. Despite improvements in the warning processes, the risk of significant loss of life remains high. That is particularly true with vulnerable communities which have higher proportions of mobile homes; however, violent tornadoes are very difficult to manage in permanent homes or buildings as well. As a result, tornado shelters have been built in some communities and have become available to the public. However, their presence is intermittent, and there are many tornado-prone areas that lack such shelters.

After a public survey, it …

Molecular Characterization Of Seminal Plasma From Boars With Divergent Sperm Quality, Notsile Hleliwe Dlamini

Theses and Dissertations

Seminal plasma (SP) is the microenvironment of spermatozoa whose composition reflects semen quality and constitutes an excellent source for detecting non-invasive biomarkers. This study characterizes good vs. poor quality semen using seminal extracellular vesicles coupled proteins and miRNA. Fresh boar semen samples were screened, centrifuged, and SP supernatants were collected for near-infrared spectroscopy (NIRS) analysis. EVs were extracted from SP (SP-EVs), characterized, and those of extremely poor or good sperm quality groups were subjected to proteomics and small RNA sequencing. Significant differences were set for P

Physiological And Yield Responses Of Soybean Cultivars To Heat And Drought Stresses, Sadikshya Poudel

Theses and Dissertations

Soybean (Glycine max L.) is an important legume crop often exposed to heat and drought stresses during reproductive and early-seed setting stages, resulting in lower yields and seed quality. Ten soybean cultivars were phenotyped for individual (drought or heat) and combined stress tolerance. Under drought, reduced stomatal conductance and increased canopy temperature significantly reduced seed number (46%) and weight (35%). Heat stress alone reduced seed number (19%) and weight (23%) compared to control. Moreover, a degree increase in daytime temperature above 32 °C during the reproductive stage reduced seed weight by 4% and 7% under well-watered and drought conditions, respectively. …

Interspecies Differences In Organophosphate Anticholinesterase Inhibition Potency And Reactivation Using Novel Oximes, Katie Elizabeth Strickland

Theses and Dissertations

Organophosphates are insecticides which result in acute adverse signs when exposed at toxic doses by animals and lead to death if left untreated. The current treatment for organophosphate toxicity includes atropine and the federally approved oxime 2-PAM. However, 2-PAM is not very effective at crossing the blood brain barrier which results in prolonged inactivation of acetylcholinesterase, which is the primary target of organophosphates, in the brain even after administration. The novel oximes, Oxime 15 and Oxime 20, are able to cross the blood brain barrier and reactivate the inhibited acetylcholinesterase. In this experiment with six animal species frequently used in …